Table 1.

Overview of all 44 studies

Study	Treatment period	Follow-up	Patients completed (n)	Age (years)	Focus on side effects	Withdrawal (%)
Adler et al51	5 weeks + 6 months	None	218 (5 weeks), 170 (6 months)	18–60	Yes	19.7
Adler et al31	6–12 months	None	550	18–65	Yes	18.5
Bejerot et al52	2 years	None	133	31.1±10.9	No	17
Bron et al15	6 weeks	None	27	18–55	No	11.1
Buitelaar et al32	12 weeks	None	401, 370 (OL)	18–63	Yes	4.3, 5 (OL)
Buitelaar et al65	56 weeks	None	155 (OL), 45 (Wd)	18–65	Yes	10.4 (OL)
Casas et al33	14 weeks	1 week	279	18–65	No	16.9 (G1), 20.7 (G2), 1 (P)
Fredriksen et al53	12 months	None	250	18–60	No	12
Huss et al54,55	66 weeks	None	725	18–60	Yes	11.3 (P1), 3.8 (P2), 5 (P3), 2.7 (ES)
Kooij et al45	7 weeks	None	45	20–56	No	0
Valdizán-Usón et al62	1 year	None	730	4–65	No	NK
Amiri et al23	6 weeks	None	60	6–15	No	0
Arabgol et al22	6 weeks	None	33	6.5–16	No	6.23
Barbaresi et al18	33.8 months	17.2 years	283	9.8 mean age	No	NK
Barkley et al46	30 days	None	83	5–13	Yes	3.6
Biederman et al21	19 weeks	None	161	6–14	No	4.35
Cherland and Fitzpatrick63	21 months	None	98	4–17	Yes	NK
Döpfner et al56	6–12 weeks	None	822	7–16	No	3.16
Efron et al47	4 weeks	None	125	104.8 months, mean age	Yes	3.2
Findling et al24	3 weeks	None	318	6–12	No	6.6
Garg et al57	8 weeks	None	69 (33 MPH)	6–14	Yes	18.18
Gau et al27	28 days	None	64	6–15	No	0
Ghuman et al16	24 months	None	27	3–5	No	6
Greenhill et al26	9 weeks	None	97	6–17	No	0
Haertling et al58	12 weeks	None	262	10.9±2.5	No	NK
Karabekiroglu et al59	15 days	None	90	5–16	Yes	8.9
Kemner et al28	21 days	None	1,323 (850 MPH)	6–12	No	4.8
Khajehpiri et al60	6 months	None	71	4–15	Yes	0
Kratochvil et al30	10 weeks	None	228 (44 MPH)	7–15 months, 7–9 weeks	No	11.4
Lee et al48	2 weeks	None	157	6–12	Yes	NK
Maayan et al17	4 weeks	None	11	4–5	No	27
MTA group34–39	14 months	24 months, 6 and 8 years	579	7–9.9	No	<1
Newcorn et al25	12 weeks	6 weeks	516	6–16	No	5
PATS group40–42	70 weeks	3, 4, and 6 years	165	3–5.5	Yes	11
Pelham et al49	3 weeks	None	70	6–12	No	0
Smith et al19	14 years	Longitudinal	131	1–17	No	NK
Ramtvedt et al64	6 weeks	None	34	11.3 mean age	Yes	2.94
Robb et al61	6–8 weeks	None	45	6–12	Yes	13.3
Silva et al14	2 weeks	None	54	6–12	No	1 (P)
Steele et al66	8 weeks	None	145	6–12	No	11.6
Stein et al50	4 weeks	None	47	5–16	Yes	NK
Swanson et al29	21 days	None	184	6–12	No	0
Wigal et al44	12 weeks	30 days	230	6–18	No	2
Zarinara et al43	6 weeks	None	38	6–13	No	5.3

Abbreviations: ES, extension study; G1, group 1; MPH, methylphenidate; NK, not known; SE, side effect; OL, open-label; P1, Phase I; P, placebo; Wd, withdrawal.